JPH04200980A - Teaching method for stud welding equipment - Google Patents

Abstract

PURPOSE:To accurately teach the welding position to industrial robots by setting the data of the position and direction of welding electrodes on a controller of one robot, then, transferring these to a controller of the other robot and driving the other robot to move the welding electrodes to the welding position. CONSTITUTION:After the controllers 11 and 21 of the plural industrial robots 1 and 2 are set on the teaching mode, the one industrial robot 1 is subjected to teaching operation and the data of the position and direction of the welding electrode 103 for materials 3 to be welded are set on the controller 11 thereof. The data of the position and direction set on the one controller 11 are then transferred to the other controller 21. While the other industrial robot 2 being subjected to teaching operation based on the transferred data, the other welding electrode 203 is then made in a coaxial state with the one welding electrode 103 and the materials 3 to be welded are held almost orthogonally by these electrodes.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a teaching method in a stud welding apparatus using a plurality of industrial robots having a playback function.

Conventional technology In conventional stud welding equipment, a welding electrode is provided at each end of the arm of a plurality of industrial robots having a playback function. Welding current is applied from a welding transformer between the - side welding electrode and the other welding electrode while the welding required portions of the plurality of materials to be welded are held under pressure by the other welding electrode facing the . A structure is known in which a portion of the material to be welded that requires welding is welded by an electric resistance method.

Problems to be Solved by the Invention In the aforementioned stud welding device, multiple industrial robots including a control device are configured individually. If the material to be welded is not positioned so that it faces accurately across the part that requires welding, the material to be welded will not only be deformed by the pressure applied by the welding electrode, but the excessive movement of the arm due to the deformation will be reflected in the teaching data. Because of this, it is not possible to accurately teach the welding position to industrial robots.

For this reason, for example, after placing the material to be welded between a plurality of welding electrodes that are spaced apart from each other in the direction below L, an operator can teach one of the plurality of industrial robots separately. The welding electrode is brought into contact with one surface of the part of the material to be welded that requires welding, and the other welding electrode is brought into contact with the other surface of the material to be welded, such as the lower surface of the part of the material to be welded. , it is confirmed whether one welding electrode and the other welding electrode are coaxially opposed to each other with the material to be welded in between.

In addition, the pressure applied by multiple welding electrodes facing each other to press and hold the material to be welded has come to depend on position data when each welding electrode contacts the material to be welded. There is.

However, the material to be welded gets in the way, and it is difficult for the operator to teach multiple industrial robots separately so that one welding electrode can be erroneously coaxially opposed to the other welding electrode with the material to be welded in between. It takes a lot of effort and time to obtain teaching data.

Means for Solving the Problems Therefore, in the present invention, when teaching a plurality of industrial robots each having a playback function and a welding electrode, the control device of one of the industrial robots is configured to control the welding electrode for the material to be welded. After setting the position and orientation data,
The position and orientation data set on one controller is transferred to the controller of the other industrial robot, and the transferred position and orientation data drives the arm of the other industrial robot. and move the welding electrode toward the part of the material to be welded that requires welding.

After the operator sets the control devices of multiple industrial robots to teaching mode, he performs a teaching operation on one of the industrial robots and tells the control device the position and orientation of the welding electrode relative to the material to be welded. Set (memorize) the data. Then, when a worker transfers the position and orientation data set in one control device to the other control device by operating the teaching switch box, the other industrial robot While the teaching operation is carried out based on the orientation data, the other welding electrode becomes coaxial with one welding electrode and holds the material to be welded approximately at right angles.

Embodiment FIG. 1 shows a stud welding apparatus used in an embodiment of the present invention, which is equipped with a plurality of industrial robots 1.2 having a playback function.

One industrial robot I is equipped with a robot main body IO installed on an installation floor (not shown) and a control device 11, such as a combination device 11 for driving and controlling the robot main body IO. This [J-bot body 10 has a gun cylinder 102 at the 1, IO+ tip.
Norindachi 1. - Fix the cylinder tube 102a of the gun cylinder +02 and the cylinder tube 102b of the operating rod 102b.
A welding electrode 103 called a tip electrode is attached to the end protruding from 02a, and the cylinder tube +02a
An air supply means 104 for supplying pressure-adjusted air to the inside of the cylinder tube 102 is connected to the air supply means 104 .

The other industrial robot 2 includes a robot main body 20 installed on the installation floor, a combination for driving and controlling the robot main body 20, and a control device 21 such as the controller.

A cylinder tube 202a of a gun cylinder 202 is fixed to the tip of the arm 201 of the robot body 20, and a welding electrode 203 called a tip electrode is attached to the end of the operating rod 202b of the gun cylinder 202 that protrudes from the cylinder tube 202a. is attached to the cylinder tube 202a, and the air supply means 04 for supplying pressure-adjusted air into the cylinder tube 202a is connected to the cylinder tube 202a.

Then, one welding electrode 103 is located above the material to be welded 3 with a distance of #lI, and the other welding electrode 203
The material to be welded 3 is placed horizontally using a jig means (not shown) so that the material to be welded 3 is spaced apart below the material to be welded 3, while the cylinder duplex l02 of the gun cylinder 102.202
While supplying air from each air supply means +04 to each of 202a and 202a, one of the welding robots 1.2 is played back with the teaching data stored in each control device 11.21. After the electrode +03 comes into contact with the − face of the part of the material to be welded 3 that requires welding, and the other welding electrode 203 comes into contact with the lower surface of the same part of the material to be welded 3 that requires welding, each gun cylinder 102 , 202 move from the solid line phase 1d on one end side of the cylinder duplexes 102a, 202a to the virtual line water position with stable pressurizing distances LA, L+- while compressing the air supplied into the cylinder duplexes 102a, 202a, Stopping, the welding electrodes 103, 203 facing each other press and hold the portion of the material to be welded 3 that requires welding, while the welding electrodes IO3, 2031?
A welding current is applied to fl from a welding transformer (not shown) for a predetermined period of time, and the portion of the material to be welded 3 that requires welding is welded by the electric resistance method. 1. The supply of welding current to the welding transformer is controlled by a welding current supply signal output from either one of the control devices 11 and 21.

On the other hand, each control device 11.2+ transmits position and orientation data from one control device 1 to the other control device 21 via wireless or wire, at least during teaching operation of a plurality of industrial robots 1.2. is now being transferred. In this embodiment, one welding electrode 103
is located above the material to be welded 3, and the other welding electrode 203
is located below the material to be welded 3, so that the operator can easily see the position and direction of the point of impact of the welding electrode on the material to be welded. This is specified for the control device of industrial robot 1-1 which has a welding electrode +03.

Here, the teaching operation of the stud welding apparatus will be described in detail with reference to FIGS. 1 and 2.

(1) First, a worker operates a teaching switch box (pendant) not shown in the diagram, and the industrial robot 1.
The two control devices 11 and 21 are set to the teaching mode, and one welding electrode +03 controls the set pressure value of the air supply means +04 according to the teaching operation signal output from the one control device II. The pressure receiver is set to a low value that will not cause deformation of the unstopped part when it is pressed, and this low pressure air is supplied to the cylinder duplexes 102a and 2 of the gun cylinders 102 and 202.
Pressure is accumulated in 02a.

(2) In this state, the operator can control one industrial robot by operating the teaching switch box.
-1 arm 101 is driven to move the welding electrode 103 toward a predetermined portion of the material to be welded 3 that requires welding. During this movement process, as shown in FIG. 2, the arm 101 of one industrial robot 1
control the posture.

(3) Next, while the operator operates the teaching switch box, as shown in FIG. The operator visually confirms that the tip of the electrode 103 has contacted the upper surface of the welding portion of the material 3 to be welded at a substantially right angle, or has come close to the upper surface of the welding portion of the material 3 to be welded.

(4) Then, after confirming that the welding electrode 103 is in contact with or close to the material to be welded 3, the operator stops driving the arm 101 of the industrial robot 1 by operating the teaching switch box. At the same time, the position data and orientation data of the arm 101 are stored in the memory of the control device 11 of the industrial robot I as a welding position by teaching.

Here, the arm as the tip position of the welding electrode +03 in one control device 11], the position data of OI is x,
y, z, arm +0 as the direction of the welding electrode 103
The unit vector in the direction of 1 is nx.

ny, nz. This unit vector nx, ny+n
If the welding electrode +03 faces directly below as shown in the third figure, z becomes O, OlI.

(5) Next, the operator operates the teaching switch box to input the position data X, Y, Z and orientation data nx, ny stored in the memory of one of the control devices 11.
, nz and the control device 2I of the other industrial robot soto 2.
Transfer to. Then, the other control device 2I stores in its memory the position data X, Y, Z and orientation data nx, ny, ny transferred from the one control device 11.

(6) Then, when the worker outputs a teaching operation signal to the control device 21 of the other industrial robot 2 by operating the teaching switch box, this control device 2 receives orientation data nx, ny, nz from the memory.
Extract the orientation data n x + fly, rl
z and calculate this inverted orientation data n X, n Y-
Arm 2 of the other industrial robot 2 based on n Z
01 to control the attitude of the other welding electrode 203 so that it is oriented in the opposite direction to one welding electrode +03, as shown in FIG.

That is, this welding electrode 203 is oriented upward so as to be substantially perpendicular to the material 3 to be welded.

(7) In parallel, the other control device 21 extracts position data x, y, z from the memory, and uses this position data x,
y, 'z and the inverted orientation data nx, ny, n
Position data X with z and preset parameters
, y, Z are calculated as , and this position data x, y,
arm 201 of the other industrial robot 2 based on z
and the other welding electrode 203, not shown in FIG.
Then, the welding electrode 103 moves directly under one of the welding electrodes 103 and faces the other welding electrode 103 .

(8) Subsequently, the other control device 2I drives the arm 201 based on the position data x, y, z, and the position data x, y, z uses the thickness tp of the material to be welded 3 as a parameter; By stopping the drive of the arm 201 at the point where , as shown in FIG. They abut at approximately right angles. As a result, one welding electrode 1
03 and the other welding electrode 203 are aligned so that they are coaxial in the -1- downward direction and sandwich the material to be welded 3.

(9) After this, the worker moves the arm 101 of one industrial robot I straight downward by a preset stable pressurizing distance LA by operating the teaching switch box, and in parallel with this, The arm 201 of the other industrial robot 2 is pressed at a preset stable pressurizing distance r, t.
, move straight upward by (1-A-r, 1,). As a result, as shown in FIG. 7, the piston +0
2c, 202c are cylinder tubes l02a, 202a
Welding electrode 1 while compressing the low pressure air supplied inside
03° 203 presses and clamps one part of the material to be welded 3 that requires welding.

(10) In a state where the welding electrodes 103, 203 pressurize and clamp the material 3 to be welded, the operator checks the posture and the dot position of the welding electrodes 103, 203 relative to the material 3 to be welded, and confirms that these are normal. If so, by operating the teaching switch box, the position and orientation data of (3) to (9) are stored as teaching data in the teaching memories of the control devices 11 and 21. This completes one cycle of teaching operation of the stud welding device.

On the other hand, after the teaching operation of the industrial robot 1.2 regarding all of the predetermined welding parts on the material 3 to be welded is completed, the operator When the teaching mode is canceled and the welding operation start switch (not shown) of the industrial robot 1.2 is operated, either the control device II or 21 sets the set pressure value of the air supply means 107I to a high value. After high-pressure air is supplied to the gun cylinders 102, 202 from the air supply means +04, the control devices 11 and 21 of the industrial robots l-1 and 2 operate the arms according to the teaching data stored in the above-mentioned teaching operation. While playing back 101.201, welding is automatically performed by the electric resistance method while the welding electrodes 103, 203 press and hold the welding required portion of the welding material 3.

Note that in the embodiment, one direction data nx, n
The other orientation data for y and nz is −n x +nv
, ny, but the other industrial robot 2 is arranged so that the moving direction of the arm 201 of the other industrial robot 2 is the same in plan view as the moving direction of the arm 101 of one industrial robot 1 By doing so, the other orientation data in 1. is nx, ny.

-n7! It is also possible to do this.

Effects of the Invention As described in -1-, according to the present invention, when teaching a plurality of industrial robots having a playback function,
A worker performs teaching operation on one industrial robot on the side where the worker can easily check the position and direction of the welding electrode's impact point on the material to be welded, and the other industrial robot Since the teaching operation is automatically performed based on the data on the position and orientation of the welding electrodes from the teaching operation, it is easy to position multiple welding electrodes so that they accurately face and sandwich the part of the material to be welded that needs to be welded. I can do it. Moreover, since the plurality of welding electrodes are positioned so as to accurately face each other across the part of the material to be welded, it is possible to prevent the material to be welded from deforming due to the pressure applied by the welding electrodes. It is possible to accurately teach the robot the welding position.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIGS. 2 to 7 are operation explanatory diagrams showing each process of the embodiment. 1.2・-Industrial robot)・1.3... Material to be welded,
10.20・Robot body, 11.21・Control device, 101,201・Arm, 103,203・・
welding electrode.

Claims (1)

[Claims] (1) A welding electrode is provided at each end of the arm of a plurality of industrial robots with a playback function, and the playback of the plurality of industrial robots allows the opposing welding electrodes to press and hold the material to be welded while resisting electrical resistance. In a stud welding device that performs welding according to the method, when teaching the plurality of industrial robots mentioned above, after setting data on the position and orientation of the welding electrode with respect to the material to be welded in the control device of one industrial robot, The position and orientation data set in the control device is transferred to the control device of the other industrial robot, and the transferred position and orientation data drives the arm of the other industrial robot to control its welding electrode. A method of teaching a stud welding device, which is characterized by moving toward a part of a material to be welded that requires welding.